Cypermethrin exposure: Implications for growth, phenotypic attributes, and biochemical responses in monosex tilapia...

The present study was conducted to evaluate the effects of exposure to sublethal concentrations of cypermethrin on growth, phenotypic traits, and metabolic and antioxidant enzymes activities of monosex tilapia (Oreochromis niloticus). The median lethal concentration (LC₅₀) of cypermethrin was initially ascertained to be 0.04 ppm after 12 h of exposure to three concentrations (0.04, 0.20, and 1.0 ppm) via the Probit analysis method. The sublethal exposures were obtained for 3 months at 0.0016, 0.008, and 0.04 ppm of cypermethrin. The growth performance, phenotypic traits, and enzymatic activity were analyzed. The research findings revealed a notable impact of cypermethrin on the growth performance of monosex tilapia, with a significant (p < 0.05) decrease in weight observed as the concentration increased. The experiment documented a significant change (p < 0.05) in the phenotypic traits of standard length, total length, tail length, trunk length, eye diameter, body area, and color patterns, but not dressing percentage. Furthermore, it was observed that the activities of amylase and protease in both the intestine and muscle decreased significantly (p < 0.05) with increasing concentrations of cypermethrin, except for amylase in the muscle, where no significant change was noted (p > 0.05). The results also demonstrated significant reductions (p < 0.05) in the activity of metabolic enzymes, specifically superoxide dismutase and catalase, following exposure to sublethal levels of cypermethrin. The study suggested that sublethal exposure of pyrethroid alters the growth, phenotypic traits, metabolic enzymes activities, and immunity of monosex tilapia.